How do scientists study microorganisms?
Grow them in large numbers
Where are microorganisms grown?
Agar jelly in a petri dish
What is agar jelly?
Jelly with nutrients added to feed microorganisms
Describe how bacteria grows?
Very quickly - can reproduce every 20 mins in optimum conditions
How does each bacterium on agar grow?
Into circular patches called colonies which can be seen by the naked eye
What grow into circular patches?
Bacterium on agar
How do scientists know how many bacteria were put onto an agar plate?
Each colony originates from one bacteria cell, so count how many colonies
What can cause inaccuracies of scientists knowing how many bacterias were originally put onto an agar plate?
Colonies merging make counting inaccurate
Why does putting fresh food in the fridge make it last longer?
Cold slows down bacteria replication
Why does a freezer make food last even longer?
Freezing almost totally stops bacteria replication